A butadiene rubber composition obtained by compounding carbon black, sulfur and other additives such as a vulcanization accelerator and the like with butadiene alone or a rubber blend of butadiene rubber and other rubber is excellent in the cold temperature resistance, wear resistance, low heat build-up, flex resistance and the like as compared with a natural rubber composition or styrene-butadiene rubber composition, so that it is used for various rubber articles.
However, when at least one adherend is the above butadiene rubber composition, there is a problem that the adhesion property to the remaining adherend before and after vulcanization is poor.
In order to solve this problem, various adhesives have hitherto been applied. For example, there are natural rubber adhesive, butadiene rubber adhesive having a solubility parameter (SP) equal or approximate to that of the adherend, and so on.
In case of applying the natural rubber adhesive, the adhesion property before vulcanization can be improved, but the adhesion property after vulcanization is insufficient because covulcanization property at the adhesion interface is insufficient to lower an interfacial adhesion force. On the other hand, in case of applying the butadiene rubber adhesive, it is possible to improve the interfacial adhesion property to enhance the adhesion property before and after vulcanization, but the effect is still insufficient.